Process for preparing aromatic polyamides with sodium carbonate hydrate as acid acceptor

Abstract

A process for preparing aromatic polyamides which comprising contacting (I) a solution or dispersion consisting of a solution or dispersion in a polar, non-basic and inert organic liquid medium of at least one starting material selected from the group consisting of I. an aromatic aminocarboxylic acid halide hydrohalogenide, Ii. a mixture of an aromatic dicarboxylic acid halide and an aromatic diamine dihydrohalogenide, and Iii. a low molecular weight aromatic polyamide having an inherent viscosity of no greater than 0.2 as measured on a solution of 0.5 gram of the polyamide in 100 ml of concentrated sulfuric acid at 30°C., with (II) an aqueous slurry consisting of a dispersion in water of a sodium carbonate hydrate.

We claim: 
     
       1. A process for preparing a fiber-forming aromatic polyamide, which comprises contacting (I) a solution or dispersion, in a polar, non-basic and inert organic liquid medium, of a low molecular weight aromatic polyamide having an inherent viscosity of no greater than 0.2 as measured in a solution of 0.5 gram of the polyamide in 100 ml. of concentrated sulfuric acid at 30° C., with (II) an aqueous slurry consisting of a dispersion in water of a sodium carbonate hydrate in a concentration of at least 5% by weight, said solution or dispersion (I) being a product obtained by reacting an aromatic diamine and an aromatic dicarboxylic acid halide in said liquid medium. 
     
     
       2. The process of claim 1 which comprises contacting said solution or dispersion (I) with said aqueous slurry (II) by mixing same with stirring at a temperature not exceeding 100° C. 
     
     
       3. The process of claim 1 wherein said polar, non-basic and inert organic liquid medium is selected from the group consisting of ethers, ketones, lactones, sulfones, halogenated hydrocarbons, nitriles and nitro compounds. 
     
     
       4. The process of claim 1 wherein sodium carbonate hydrate is present in a concentration of 10-60% by weight. 
     
     
       5. The process of claim 1 wherein said aromatic diamine and aromatic dicarboxylic acid halide are reacted at a temperature not exceeding 100° C.